Airmen&#39;s helmets



April 1959 M. J. o: LOBELLE ET AL 3,438,060

AIRMENS HELMENTS Sheet Filed Sept. 6. 1966 MVE/VTORS MAACEI. (1'0. LOBELLE J N GREGORY April 15, 1969 M. J. O. LOBELLE ET AL AIRMEN'S HELMENTS Sheet Filed Sept. 6. 1966 United States Patent US. Cl. 26 8 Claims ABSTRACT OF THE DISCLOSURE A pressurized aviators helmet is disclosed in which the :forces of pressurization tending to urge the helmet upwardly with respect to the wearers head are neutralized by an unpressurized area at the top of the helmet substantially equal in area to the area of the neck of the wearer. The unpressurized area is created solely by an annular resilient member attached to the interior of the upper portion of the helmet and which in use contacts the head and/or hair of the wearer directly and the construction thus avoids the use of the inner bladders of the prior art which surround the entire head except for the facial area of the wearer.

In pressurized helmets worn by airmen the effect of the internal pressure is to produce a resultant upward force owing to the lack of downwardly acting pressure over the area represented by the neck of the wearer. This upward force would cause considerable discomfort to the wearer and is frequently overcome by the use of some form of holding-down harness which may need to be adjusted according to the internal pressure in the helmet.

In accordance with the present invention the inner side of the top of a pressurized airmans helmet is provided with an annular member which when the helmet is pressurized forms a seal with the top of the head of the wearer to define an unpressurized area substantially equal to the area of the neck of the wearer. The result is that the forces acting in a vertical direction as a result of the pressurization are substantially equalized. In other words the upward force on the helmet caused by the pressurization is reduced so as to substantially equalize the downward force caused by the pressurization thus avoiding the resultant upward force referred to. It might be thought that difliculty would be experienced in obtaining an eflicient seal owing to the presence of hair between the annular member and the skin of the wearer but rather surprisingly this is not so and an effective seal may be obtained with a variety of different types of annular member. In any case the commonest method of pressurizing a pressurized helmet is to use the oxygen supply so that if there is any small leakage this would be constantly made good.

The invention is applicable to helmets which are for use with partial-pressure suits as well as to helmets which form part of a full-pressure suit. In the form case however a separate neck-seal needs to be provided in the neck of the helmet.

Constructions of pressurized helmets in accordance with the invention will now be described in more detail by way of example and with reference to the accompanying schematic drawings in which:

FIGURE 1 is an elevation in cross-section of one such helmet of the type designed for use with a partial-pressure suit;

FIGURE 2 is a less-detailed elevation in cross-section of another such helmet also of the type designed for use with a partial-pressure suit; and

3,438,060 Patented Apr. 15, 1969 FIGURE 3 is a less-detailed elevation in cross-section of another helmet in accordance with the invention and of the type which forms part of a full-pressure suit.

Referring first to FIGURE 1, the helmet has a rigid shell 1 having a face aperture for the wearer 2 which can be closed by a visor 3 which is pivoted on side arms at 24. The visor may be controlled in the manner described in our Patent No. 3,128,469. An oxygen mask 4 fits over the wearers mouth and nose and is secured to a pivoted front part 5 of the rigid shell by a resilient connection 6. The front part can be swung outwardly together with the oxygen mask 4 to enable the helmet to be fitted or removed from the wearers head. An oxygen breathing line (not shown) is connected to an inlet 7 in the front part 5 and supplies oxygen to the mask 4 from an oxygen supply regulator (not shown). The regulator also supplies oxygen to pressurize the space 8 within the helmet through a control valve (not shown) in the mask 4 in the conventional way.

The helmet includes a neck-seal which is in the form of an inflatable tube 19 which is not annular but is split so that its ends can be separated to enable the wearers head to pass through the neck of the helmet. The tube has a cros-section similar to a figure eight and is inflated with oxygen from the high pressure side of the oxygen supply regulator through a line secured to an inlet 21. The tube 19 is connected by a flexible pipe 20 to another inflatable tube 22 also having a cross-section similar to a figure eight but which is annular. This tube 22 is secured to resilient pads 25 which are aflixed to the interior of the helmet shell 1. The tubes 19 and 22 are inflated at the same pressure when the helmet is pressurized but are at a higher pressure than the pressure in the space 8. The pressure in the tubes may be pre-set so as to ensure that there is always a pressure diflerence between the tube pressure and the pressure in the space even when the latter is at its maximum value. Alternatively the tubes can be made to sense the pressure i the space and maintain a higher pressure in themselves so that a corresponding pressure difference exists for any pressure in the space 8. Both tubes tend to take up a circular crosssection when inflated but are compressed slightly to form seals with the wearers skin.

The tube 22 defines a space 12 on the top of the wearers head which remains unpressurized. A vent '13 is provided in the top of the shell 1 so that any leakage past the tube 22 does not cause the space 12 to become pressurized. The space 12 has an area substantially equal to the area of the neck of the helmet (or wearer), that is to say the cross-sectional area defined by the tube 19, and it can thus be seen that the result is that the upward force which is associated with conventional helmets is eliminated for the reasons given previously.

A seal is provided between the edges of the visor 3 and the shell 1 by an annular inflatable tube 23 which is connected by a flexible pipe 26 to the tube 22 so that all three tubes inflate together.

The helmet shown in FIGURE 2 is basically similar to that which has just been described and the same reference numerals are used to indicate similar components. However instead of the inflatable tubes 19 and 20, a splitring 9 and a ring 11 respectively of resilient foam padding are provided. The foam padding is rendered pressure-tight by means of an impermeable skin which covers it. The ring 11 and the split-ring 9 are compressed when the helmet is being worn and serve the same purpose as the tubes 19 and 22. The split-ring 9 is provided with a socalled reflected edge seal consisting of a flexible lip 10 of rubber or similar material. When the helmet is pressurized, the internal pressure in the space 9 presses the lip 10 against the wearers neck thus forming a seal.

In addition as previously mentioned the split-ring 9 of foam padding is compressed and also forms a seal.

The helmet of FIGURE 2 has a resilient padded ring 14 in place of the inflatable tube 23 which provides a seal between the edges of the visor when the latter is in the lower closed position.

The helmet shown in FIGURE 3 forms part of a fullpressure suit and is attached to the body part 16 of the suit by a pressure-tight lock 17 carried on a rotatable neck carried on a rotatable neck race. The same reference numerals are again used for similar components and it will be seen that the neck-seal is no longer present. The front part of the helmet does not open as in the two constructions previously described.

Referring in particular to the annular member 11, it will be apparent that this differs from that shown in FIG- URE 2 in that a reflected edge seal in the form of an outwardly extending lip 18 is attached to it. As in the case of the similar seal which forms part of the neck seal in FIGURE 2, this lip may be of rubber or a similar material and is pressed against the wearers head by the pressure in the pressurized space 8 to give an improved seal. Naturally a reflected edge seal could be provided in addition to the annular member in the construction of FIGURE 1 or alternatively the annular member alone could be provided in the construction of FIGURE 3.

It should be noted that in the construction of helmet shown in FIGURE 3 it is the neck 15 of the suit body portion 16 which fits around the wearers neck rather than the neck of the helmet as is the case in the other two illustrated constructions. As is shown, there does not have to be a seal between the wearers neck and the suit and thus the cross-sectional area of the wearers neck and the neck of the suit need not be the same.

It is clearly desirable that in all constructions leakage from the pressurized space 8 should be as small as possible. This can be improved by facing the annular member 11 whether in the form of an inflatable tube or of foam rubber with material having a similar texture to hair, such as artificial hair or chamois leather. This cooperates with the wearers hair to give an improved seal.

We claim:

1. A pressurized airmans helmet comprising:

a hollow substantially rigid shell;

a pressure-tight neck-sealing member attached to said shell;

means for sealing an annular area between the top of the head of the wearer and the inner surface of said shell, said means defining an area substantially equal to the area defined by said neck-sealing memher, said means consisting solely of an annular resilient member attached only to the inner surface of said shell and adapted to engage the head and hair of the wearer; and

vent means located in the top of said helmet for venting said area defined by said annular resilient member to the exterior of said helmet, the remainder of said helmet being fluid tight.

2. A helmet according to claim 1 in which the said resilient member is an inflatable tube which is inflated at a higher pressure than the said helmet when the latter is pressurized.

3. A helmet according to claim 1 in which the said resilient member includes a flexible lip extending outwardly and is such that when the said helmet is presurized, the said lip is pressed against the head of the wearer by internal pressure.

4. A helmet according to claim 1 in which the said sealing surface is faced with a textured material.

5. A pressurized airmans helmet comprising:

a hollow substantially rigid shell;

a pressure-tight attachment means attached to said shell for attaching said helmet to a full pressure suit;

means for sealing an annular area between the top of the head of the wearer and the inner surface of said shell, said means defining an area substantially equal to the area (defined by said neck-sealing member) of the neck of the wearer, said means consisting solely of an annular resilient member attached only to the inner surface of said shell and adapted to engage the head and hair of the wearer; and

vent means located in the top of said helmet for venting said area defined by said annular resilient member to the exterior of said helmet, the remainder of said helmet being fluid tight.

6. A helmet according to claim 5 in which said resilient member is an inflatable tube which is inflated at a higher pressure than the said helmet when the latter is pressurized.

7. A helmet according to claim 5 in which said resilient member includes a flexible lip extending outwardly and is such that when said helmet is pressurized, the said lip is pressed against the head of the wearer by internal pressure.

8. A helmet as defined by claim 5 in which the said sealing surface is faced with a textured material.

References Cited UNITED STATES PATENTS 622,677 4/1899 Gallagher et al. 128-142.7 1,635,456 7/1927 Bowditch 2--181 1,945,919 2/1934 Seijo 128-142 2,411,831 11/ 1946 Lehmberg et al 2-18l 2,628,361 2/1953 Heyck 2l81 2,935,985 5/1960 Andrews et al.

3,149,632 9/1964 Colley 2-6 XR 3,295,522 1/ 1967 Johnson 128-142] XR JAMES R. BOLER, Primary Examiner.

US. Cl. X.R. 

